CN102017783B

CN102017783B - Network entity selection

Info

Publication number: CN102017783B
Application number: CN200880128835.8A
Authority: CN
Inventors: T·贝林
Original assignee: Nokia Siemens Networks Oy
Current assignee: Nokia Solutions and Networks Oy
Priority date: 2008-04-25
Filing date: 2008-04-25
Publication date: 2015-05-27
Anticipated expiration: 2028-04-25
Also published as: US10051012B2; EP2272300A1; US20180352008A1; US20110032930A1; PL2272300T3; AU2008355388B2; AU2008355388A1; WO2009129861A1; CN102017783A; EP2272300B1; US11388202B2; CA2722014A1

Abstract

There are disclosed measures of network entityselection, for example comprisingfurnishing an identity of a network entitybeing pre-selected by a first network apparatus, andproviding verification information for said pre-selected network entityidentity, enabling to verify whether the pre-selected network entity identity is applicable for network entity selection at a second network apparatus.

Description

Network entity is selected

Technical field

The present invention relates generally to that the network entity in communication system is selected.Especially, the network entity that embodiments of the invention relate in the circuit switched core network of communication system is selected.By the present invention, the network entity of any kind can be selected, such as media gateway.

Background technology

Current, standardization effort that is current and future communication systems is generally intended to realize larger convergence, flexibility and technology and independently realizes.Especially, some effort relates to the carrying individual cores network in communication system.Although this specification is exemplarily with reference to circuit switching (CS) territory of core network (CN), such as, but following content can also be applied to the packet-switched domain of core network and even the network portion except core network itself, public land mobile network (PLMN).

However, Fig. 1 illustrates the example logic network architecture of circuit switched core network, below illustrates and can apply described principle to it based on it.

Have nothing to do with the details of Fig. 1, on the one hand, some element of other number any can be there is, on the other hand, can also exist in-between arbitrary number intermediary element (as in such as other figure describe).Although the name that Fig. 1 uses relates to 3GPP (third generation partner program) term, but it should be noted that this type of term (same when using hereinafter) is only intended to exemplarily, and other element any having and name according to the difference of different term can be used, as long as general principle, condition and/or prerequisite are similar.This is applicable to such as illustrational individual component and separately interface (reference point).Especially, when carrying out reference as the non-limiting example being used for network entity to media gateway hereinafter, other network entity any (namely, the funtion part of such as network element or network element) applicable equally, be such as attached to and perform IP and/or port translation but the gateway transmitting the Session Border Controller (SBC) of media pellucidly.

Comprise Liang Ge Information Mobile Service switching center (MSC) according to the example logic CS core network architecture of Fig. 1, one of them is Gateway Mobile services switching center (GMSC).Although can also use and move integrally Services Switching Centre, illustrate and have respectively by as the MSC/GMSC server (G/MSC-S) of controlled entity and the combination MSC node being connected the decomposition framework (i.e. soft-exchange construction) that media gateway (MGW) forms.Exemplarily, core network operationally with GERAN (GSM EDGE radio access network; GSM=global system for mobile communications; EDGE=GSM evolution enhanced data rates) be connected with UTRAN (universal land radio access web) and PSTN (public switch telephone network).

As such as according to the call control protocol in the network architecture of the CS core network of Fig. 1, propose some amendment that carrying independent call controls (BICC) and Session initiation Protocol, namely there is the Session initiation Protocol of (encapsulated) ISDN (Integrated Service Digital Network(ISDN)) User Part (SIP-I) of encapsulation.Although BICC and SIP-I can be considered as the alternative controlled for call/session, so-called optimization and delay media gateway option program are proposed for based on BICC and the Call-Control1 based on SIP-I.

When the Call-Control1 based on SIP-I, current defined optimization MGW selects to comprise a node (such as MSC/GMSC server) and selects media gateway (MGW) according to some rule and the identity of selected media gateway is signaled to another node (such as, MSC/GMSC server) in SIP-I message.Therefore, make another node receiving SIP-I message can select identical media gateway, if it has the Mc interface to selected media gateway, therefore save media gateway and transmit Internet resources.Current defined delay MGW selects the receiver being provided for SIP-I message select its preferred media gateway and send the identity of selected media gateway back to previous node to make this node can select the chance of identical media gateway.In addition, the next SIP-I node taken in when described program allows supplier (offerer) " proposition " media gateway identity to be sent to and can to obtain (seizes) media gateway in subsequent node.

Due to described optimization with delay media gateway option program is current is defined as optional procedure, so communication system can be predicted or network will comprise the node supporting this class method and the node not supporting this class method.This causes compatibility issue when the intermediate node in this class method suitably can not be processed each (signaling) business.

In addition, for encoding to the identity of selected media gateway from a node-node transmission to another node in optimization and delay media gateway are selected, not yet to define specific program.This also may cause compatibility issue.

One for media gateway identity coding can imagine that method is the use of Session Description Protocol (SDP) attribute, causes at SIP, is more specifically transmit SDP in SIP-I signaling.

In view of the above-mentioned washability of general two kinds of media gateway option programs and SDP are as the use of the specific coding for media gateway identity, this means it is not that each node in CS CN can understand this type of new SDP attribute of encoding to MGW identity.According to current SIP program, intermediate node will pass on any unknown SDP attribute pellucidly, such as, to the attribute that MGW identity is encoded.But, suppose that source node MSC A has selected MGW A and in this type of SDP MGW identity attribute, indicated its identity, and centre (Call-Control1) Node B not understanding MGW identity SDP attribute passes on unknown properties insert another MGW B towards subsequent node in IP signaling, and the subsequent node that so passed on MGW identity A may mislead such as MSC C selects suboptimum MGW A simultaneously.This is sent to MGW B from MGW A by causing wherein user-plane traffic and is turned back to the configuration of MGW A.

It should be noted and only have when calling out (namely, user-plane traffic) remain on the MGW (i.e. " logic MGW ") controlled by two servers (such as MSC A and MSC B) two subregions (partition) between identical media gateway in, process by the resource of the media gateway of the calling of two server controls save be only possible.If on the other hand, MSC server knows that it can not realize this optimization, then it can use other standard to select optimization to make MGW, such as arrive wherein that it judges that the proximity of the down hop of the connection that will set up of route or calling (please notes, when relating to certain and connecting or call out, the following network address can also be represented for link address).

Above-mentioned shortcoming is unfavorable for the quiet run wherein performing current and future communication systems and network that certain media gateway is selected.

In order to overcome this type of unfavorable effect, should be noted that current media gateway option program is defined as optionally.Therefore, any solution of ordering any node to operate (in media gateway is selected) does not in some way meet its optional character, is therefore unsuitable.In this regard, such as the media gateway that the media gateway based on BICC selects the compulsive measures taked not to be suitable for based on SIP or SIP-I is selected.This is because will require this attribute of each node recognition in order core network to SIP or SIP-I application class like program, this will conflict with the expectation washability of program.Especially, can dispose the Session Border Controller (SBC) serving as SIP-ALG (application level gateway), its object for IP (Internet Protocol) address transition and fire compartment wall inserts the user plane entity of not transcode (transcode).Meanwhile, this type of SBC can pass on unknown SDP attribute pellucidly.

Relative to above, should be noted that also there is same or similar shortcoming for the selection of the network entity except media gateway, such as, be attached to and perform IP and/or port translation but the gateway transmitting the Session Border Controller (SBC) of media pellucidly.

Therefore, there is not any feasible solution to above-mentioned shortcoming, particularly select about the media gateway such as based on SIP-I.

Summary of the invention

Realize the present invention and embodiment is to solve one or more above-mentioned shortcoming.

Therefore, the present invention and embodiment intention alleviate the shortcoming in network entity selection, the compatibility issue such as caused by its optional character.

According to illustrative aspects of the present invention, disclose:

The method set forth in-any one in claim 1 to 8,

The method set forth in-any one in claim 9 to 19,

The equipment of setting forth in-any one in claim 20 to 27, and/or

The equipment of setting forth in-any one in claim 28 to 38.

According to an illustrative aspects of the present invention, provide a kind of method that network entity is selected, comprise the identity of supply (furnishing) by the network entity of first network equipment preliminary election, and being provided for the authorization information of described preselected network entity identities, the network entity making it possible to check described preselected network entity identities whether to be applicable to second network equipment place is selected.

Improve further or amendment according to it, what be suitable in the following is one or more:

-described method is also included in conversation launch protocol message and preselected network entity identities and verification msg is sent to the second equipment,

The supply of-identity is included in Session Description Protocol attribute encodes to preselected network entity identities, and the providing to comprise and add the network address of described preselected network entity to described Session Description Protocol attribute of authorization information, and/or

-described method also comprises the network address of preselected network entity is defined as Session Description Protocol connection data, and is sent as Session Description Protocol connection data the network address defined like this in conversation launch protocol message.

According to an illustrative aspects of the present invention, provide a kind of method that network entity is selected, comprise obtain by the identity of the network entity of the first equipment preliminary election and the authorization information for described preselected network entity identities, and based on this authorization information come inspection institute obtain network entity identity whether be applicable to network entity select.

-described method is also included in conversation launch protocol message and receives preselected network entity identities and verification msg,

-described conversation launch protocol message comprises the preselected network entity identities of the preselected network entity in Session Description Protocol attribute and the network address of the network address and the preselected network entity as Session Description Protocol connection data,

-described method also comprises the network address from Session Description Protocol connection data retrieval preselected network entity, and the acquisition of authorization information comprises the network address obtaining preselected network entity from Session Description Protocol attribute,

-described inspection comprises compares with the network address retrieved of Session Description Protocol connection data mutually by the network address obtained in conversation description protocol attribute,

If-described method also comprises this, to compare the network address that display compares be equal, then obtained network entity identity is used for network entity to select, and if this compares display, the network address is unequal, then abandon obtained network entity identity, and/or

-described method also comprises removes Session Description Protocol attribute from conversation launch protocol message.

According to any one in above-mentioned aspect, the network address of described preselected network entity can comprise the Internet Protocol address for the communication via described network entity, and/or described method can be performed by Information Mobile Service switching center equipment, with/described method can be performed in the circuit switched core network of communication system, and/or described network entity can be media gateway.

According to an illustrative aspects of the present invention, provide a kind of equipment, comprise for supplying by the device of the identity of the network entity of first network equipment preliminary election, for the device that the authorization information being provided for described preselected network entity identities, the network entity that makes it possible to check described preselected network entity identities whether to be applicable to second network equipment place are selected.

-described equipment also comprises the device for preselected network entity identities and verification msg being sent to the second equipment in conversation launch protocol message,

-described feeding mechanism comprise in Session Description Protocol attribute to the device that preselected network entity identities is encoded, and described generator comprises the device for the network address of preselected network entity being sent to described Session Description Protocol attribute, and/or

-described equipment also comprises the device for the network address of preselected network entity being defined as Session Description Protocol connection data, and described dispensing device is also configured to be sent as Session Description Protocol connection data the network address defined like this in conversation launch protocol message.

According to an illustrative aspects of the present invention, provide a kind of equipment, comprise the device for obtaining by the identity of the network entity of the first equipment preliminary election and the authorization information for described preselected network entity identities, and whether the network entity identity obtained for coming inspection institute based on described authorization information is applicable to the device of network entity selection.

-described equipment also comprises the device for receiving preselected network entity identities and verification msg in conversation launch protocol message,

-described receiving system is configured to receive conversation launch protocol message, this conversation launch protocol message comprises the preselected network entity identities of the preselected network entity in Session Description Protocol attribute and the network address of the network address and the preselected network entity as Session Description Protocol connection data

-described equipment also comprises the device for the network address from Session Description Protocol connection data retrieval preselected network entity, and described obtaining means comprises the device of the network address for obtaining preselected network entity from Session Description Protocol attribute,

-described verifying attachment comprises the device for mutually being compared with the network address retrieved of Session Description Protocol connection data the network address obtained in conversation description protocol attribute,

-described equipment also comprise for show at described comparison means the network address of comparing equal obtained network entity identity is used for the device that network entity selects, with the device for abandoning obtained network entity identity under show the unequal situation in the network address that compares at described comparison means, and/or

-described equipment also comprises the device for removing Session Description Protocol attribute from conversation launch protocol message.

According to any one in above-mentioned aspect, the network address of described preselected network entity can comprise the Internet Protocol address for the communication via described network entity, and/or described equipment can comprise Information Mobile Service switching center equipment, with/can be arranged in the circuit switched core network of communication system by described equipment, and/or described network entity can be media gateway.

According to an illustrative aspects of the present invention, provide a kind of computer program comprising program code devices, described program code devices is arranged to perform when running on the processor of equipment according to any one in any one method in above-mentioned.

According to an illustrative aspects of the present invention, provide a kind of data structure comprising the Session Description Protocol attribute comprising the identity of media gateway and the network address of media gateway.

According to an illustrative aspects of the present invention, provide a kind of data structure comprising conversation launch protocol message, this conversation launch protocol message comprises the network address of the identity of the media gateway in Session Description Protocol attribute and the network address of media gateway and the media gateway as Session Description Protocol connection data.

The other side according to the present invention and embodiment, embodiment and amendment has been set forth in each dependent claims.

By exemplary embodiment of the present invention, the network entity that select can be such as media gateway.

By exemplary embodiment of the present invention, such as provide and detect at network entity (such as media gateway) identity of a network equipment place preliminary election or identifier and by least one mode of the not meeting property between the network entity identity of reception that uses in the network entity selection course at another network equipment place or identifier, wherein, selected network entity identities or identifier are passed to another network equipment by via intermediate node.This type of detection such as can comprise the device that a described network equipment is provided for indicating this type of not meeting property, and another network equipment described can be identified by the device provided like this described in not meeting property.

By exemplary embodiment of the present invention, such as, provide some and avoid the network entity (such as media gateway) at the network equipment (such as Information Mobile Service switching center) place to select by the measure that misleads from network entity (such as media gateway) identity of previous node or identifier and the measure avoiding needing the needs being supported in all nodes in communication system or network or network entity (such as media gateway) identity in the network equipment or identifier (namely it is selected and/or encodes).

Accompanying drawing explanation

Hereinafter, in more detail the present invention is described in the mode of non-limiting example with reference to the accompanying drawings, in the accompanying drawings

Fig. 1 illustrates the logical network framework of the circuit switched core network wherein can applying exemplary embodiment of the present invention,

Fig. 2 illustrates the flow chart of the first method according to exemplary embodiment of the present invention,

Fig. 3 illustrates the flow chart of the second method according to exemplary embodiment of the present invention,

Fig. 4 illustrates the flow chart of the third method according to exemplary embodiment of the present invention,

Fig. 5 illustrates the flow chart of the 4th method according to exemplary embodiment of the present invention,

Fig. 6 illustrates the signaling diagram selected according to the optimization media gateway of exemplary embodiment of the present invention,

Fig. 7 illustrates the signaling diagram selected according to the optimization media gateway with intermediate node of exemplary embodiment of the present invention,

Fig. 8 illustrates the signaling diagram selected according to the delay media gateway of exemplary embodiment of the present invention,

Fig. 9 illustrates the signaling diagram selected according to the delay media gateway with intermediate node of exemplary embodiment of the present invention,

Figure 10 illustrates the schematic block diagram of the first equipment according to exemplary embodiment of the present invention,

Figure 11 illustrates the schematic block diagram of the second equipment according to exemplary embodiment of the present invention,

Figure 12 illustrates schematically showing according to the first data structure of exemplary embodiment of the present invention, and

Figure 13 illustrates schematically showing according to the second data structure of exemplary embodiment of the present invention.

Embodiment

With reference to specific non-limiting example, the present invention is described in this article.Those skilled in the art will be appreciated that and the invention is not restricted to those examples, and can broadly apply.

Especially, main phase describes the present invention and embodiment for circuit switching (CS) core network (CN) that can define according to 3GPP specification be used as the non-limiting example of network configuration.Similarly, the description of the embodiment provided herein specifically refers to directly associated term.In addition, main phase is selected to describe the present invention and embodiment, although the selection of the network entity of any kind or network element is applicable equally for media gateway.Further, use SDP and SIP term for session signaling object, other session signaling mechanism any can also be utilized, as long as meet described feature simultaneously.This type of term only uses under the background of proposed non-limiting example, and does not certainly limit the present invention in any way.

For exemplarily as the basic logic network architecture of the basis of following exemplary illustration, reference is carried out to Fig. 1.

Put it briefly, embodiments of the invention relate to the checking of network entity (such as media gateway) identity that may will use in network entity (such as media gateway) option program.For this reason, embodiments of the invention comprise especially being configured between the network equipment or node and send the method and apparatus of network entity (such as media gateway) identity and the example of software and data structure with signal.As a non-limiting example, this type of embodiment can be configured to for based on the signaling of Session initiation Protocol (SIP) of Session initiation Protocol of ISDN User Part (SIP-I) such as with encapsulation, wherein, Session Description Protocol (SDP) data are such as transmitted.This type of signaling such as can occur between according to the Information Mobile Service switching center (MSC) realized with overall or compound mode (in the case of the latter between mobile MSC server) of Current standards (such as by 3GPP, ETSI etc.) in the circuit switched core network of such as public land mobile network (PLMN).

Hereinafter, for simplicity, term " media gateway " is used as the non-limiting example of the network entity for any kind, and described instruction content is not limited thereto.

Fig. 2 illustrates the flow chart of the method according to exemplary embodiment of the present invention.

According to the method for Fig. 2, the identity (operation S201) of supply preliminary election media gateway (MGW), and authorization information (operation S202) is provided.The authorization information provided like this is associated and the MGW making the network equipment receiving MGW identity and authorization information check the media gateway identity received so whether to be applicable to this equipment place selects with selected MGW identity.Therefore, can avoid the reception network equipment in media gateway is selected because the identity of preliminary election media gateway (sending the selection of network equipment place) is being misled by changing in some way or become indefinite to the transmission period of the reception network equipment from the transmission network equipment.

Therefore, can preferably in the initiation side of media gateway option program, such as perform the method for Fig. 2 at first network equipment (such as MSC) place or the transmitter side place of any intermediary network device (such as MSC) in MGW selects.

That is, the method for Fig. 2 describes the mode that media gateway that MGW identity from network to remote network equipment (such as MSC) instruction (such as via intermediate node) that how pass transparently through is not practicable for remote network equipment place is selected.

Fig. 3 illustrates the flow chart of the method according to exemplary embodiment of the present invention.For the method described like this, exemplarily suppose to transmit MGW identity in the SDP attribute in SIP or SIP-I message.

According to the method for Fig. 3, by carrying out to preliminary election MGW identity the identity (operation S301) that coding supplies preliminary election media gateway (MGW) in SDP attribute, and pass through the network address of preliminary election media gateway, the network address being namely selected to corresponding connection or the calling that will set up, also add SDP attribute to (to please note to provide authorization information, when relating to certain and connecting or call out, the following network address can also be represented for link address).Although be not limited thereto, the network address (link address) can be used to IP (any Internet Protocol imagining version, such as IPv4 or the IPv6) address of the preliminary election media gateway transmitting user-plane traffic.In addition, the preliminary election MGW identity of preliminary election media gateway and network (IP) address can be combined in same SDP attribute/expand or different SDP attribute/expansions of being associated with each other.This generic attribute can be such as session level attribute or media-level attributes.The network address can be such as according to " link address " transmitted in the SDP c line of RFC 4566.Or, as an alternative or except SDP attribute, any other of the transmission for these elements can also be used can to imagine parameter or message field.In operation S303, the network address (such as IP address) of preliminary election media gateway is defined as SDP connection data.That is, according to current SDP program, the network address (such as IP address) for the corresponding connection that will set up or calling is included in each parameter.For the purpose of this description, although without limitation, suppose that this parameter is according to SDP specification " c line ".The network address (operation S303) be included in SDP " c line " is certainly identical with the network address of adding above-mentioned SDP attribute (operating S302) to.Subsequently, SIP (being more specifically SIP-I) message is sent in operation S304, as MGW identity selected by SDP attribute and authorization information (namely it at least comprise, such as IP address), and preferably also comprise define grid (IP) address as SDP " c line ".Described message this attribute kit can be contained in SDP provide or SDP response in.Therefore, the method of Fig. 3 can such as perform at the initiation side place of media gateway option program, such as performing first network equipment (such as MSC) place that MGW selects, or the transmitter side place of any intermediary network device (such as MSC) in MGW selects performs.

Fig. 4 illustrates the flow chart of the method according to exemplary embodiment of the present invention.

According to the method for Fig. 4, in operation S401, obtain preliminary election or recommend identity and the authorization information that is associated of MGW identity therewith of media gateway (MGW).In operation S402, whether inspection preselected network entity identities is applicable to the network entity performing equipment of the present invention, i.e. second network equipment place is selected.Therefore, the identity receiving the preliminary election media gateway that second network equipment uses due to intention can be avoided to be misled in media gateway selection course by changing in some way or become indefinite to the transmission period of reception second network equipment from the transmission network equipment.Therefore, such as can perform the second network equipment place of MGW selection course in the termination side of media gateway option program, such as or perform the method for Fig. 4 at the receiver side place of any intermediary network device (such as MSC) performing MGW selection course.

Fig. 5 illustrates the flow chart of the method according to exemplary embodiment of the present invention.For the method described like this, exemplarily suppose to transmit MGW identity in the SDP attribute in SIP or SIP-I message.

According to the method for Fig. 5, the identity receiving preliminary election or recommendation media gateway (MGW) in SIP or SIP-I message and the authorization information (operating S501) be associated with this preliminary election MGW identity, obtain described identity and authorization information (operation S502) from its SDP attribute then thus, namely.Described message this attribute kit can be contained in SDP provide or SDP response in.According to the non-limiting example corresponded to according to the non-limiting example of the method for Fig. 3, the message received comprises the preliminary election media gateway identity of the preliminary election media gateway in SDP attribute and the network address of the network address and the preliminary election media gateway as SDP connection data, wherein, the described network address can be preferably IP address.If like this, here hypothesis so, then operate 502 and obtain network (such as IP) address of preliminary election media gateway as verification msg.In SIP or the SIP-I message received like this, according to current SDP specification, SDP connection data is included in such as SDP " c line ", wherein, can be changed this connection data in " c line " by the intermediate node on the passage sent between the network equipment and the reception network equipment.Also from connection data, i.e. this connection data of retrieval " c line ", the network address (operation S503) of such as i.e. preliminary election media gateway.Then, in order to check the MGW identity received, in operation S504, by network (IP) address in SDP " c line " compared with the network address in above-mentioned SDP attribute.If the comparison display network address of operation S504 is equal, the MGW identity namely received is applicable to MGW and selects, then the MGW identity received is used for MGW and selects (operation S505).Otherwise if the comparison display network address of operation S504 is unequal, the MGW identity namely received is not practicable for MGW and selects, then the MGW identity received abandoned and be not used in MGW selection (operation S506).Under any circumstance, comprising by the SDP attribute of the IP address of the preliminary election MGW identity and preliminary election MGW identity sending network equipment interpolation (operation S507) of receiving can be removed from SIP or sip message.Alternatively, SIP or SIP-I transfer of messages warp unshowned in Fig. 5 can revised like this is to another node or the network equipment.Therefore, can in the termination side place of the equipment of execution media gateway option program or the method performing Fig. 5 at the receiver side place of any intermediary network device (such as MSC).

For the more details of the said method about Fig. 2 to 5, reference is carried out to the exemplary process diagram of Fig. 6 to 9.

Fig. 6 illustrates the signaling diagram selected according to the optimization media gateway of exemplary embodiment of the present invention.

According to Fig. 6, the first equipment MSC A asks the reserved of new destination node (termination) from media gateway MGW A.MGW A confirms reserving of this destination node and indicates it to be assigned with network (IP) address ip A (step 1) to this destination node.It should be noted that MGW can comprise multiple interfaces with independent IP address.MSC A is preliminary election media gateway MGW A therefore, and wherein, the respective call that network address IPA is used for carrying out via preliminary election media gateway is set up.In step 2, MSC A generates SIP or SIP-I message, in this case for SIP invites (SIP INVITE), and sends it to subsequent node B.As non-limiting example, the message of such transmission comprises the SDP of encapsulation, it comprise describe by GMW A according to SDP " c line " (" c=") of the network address IPA of normal SIP/SDP regular allocation and describe unique preliminary election (therefore recommend) MGW identity MGWIDA and corresponding to the SDP attribute (" a=") being called " mgwid " of the interpolation network address IPA of preliminary election media gateway as verification msg.When receiving this message, especially, MSC B determines the destination of media (i.e. user-plane traffic) based on " c line " content, i.e. IPA.Further, find that content, the i.e. IPA of " c line " equal the content of the verification msg in SDP attribute, i.e. IPA.Therefore, discovery should by the media gateway identity MGWIDA received in SDP " mgwid " attribute for media gateway selection course.Also determine that it has towards the control interface of MGW A and judges reserving in this media gateway place request resource.Its instruction MGW reserves resource towards the destination node of IP address ip A transmission media and reserves resource (step 3) for another destination node.The IP address ip A that media gateway MGW A determines the first destination node is the IP address of oneself and configures some inner shortcut and be connected with destination node reserved in step 1 by this destination node, thus saves and outsidely transmit resource and internal processing resource.In step 4, MGW A confirms reserving and indicating it to the second destination node distribution network (IP) address ip A2 of resource.For the object continuing call setup, Node B itself can generate corresponding SIP or the SIP-I message for passing on, in this case for SIP invites (SIP INVITE) (step 5).In this message, in SDP " c line ", insert network address IPA2.This message can also comprise SDP attribute " mgwid " as previously mentioned.

Therefore, according to the operation of Fig. 6, MSC A is configured to perform any one in Fig. 2 and 3 methods at transmitter side place, and Node B be configured to receiver side place perform Figure 4 and 5 method in any one and perform at transmitter side place in the method for Fig. 2 and 3 any one.

Fig. 7 illustrates the signaling diagram selected according to the optimization media gateway with intermediate node of exemplary embodiment of the present invention.Suppose that intermediate node B does not support that the MGW based on SIP or SIP-I had according to the MGW identity of SDP coding selects.

The step 1 of Fig. 7 and 2 is equivalent to those of Fig. 6.Contrary with the Node B of Fig. 6, the Node B of Fig. 7 does not have the interface with media gateway MGW A, but has the media gateway MGW B using network address IPB.Node B such as SBC or SIP-ALG does not support optimization MGW to select and relevant " mgwid " attribute, receives SIP invite (SIP INVITE) message and ignore " mgwid " attribute from MSC A.It inserts the MGW B of oneself, and this MGW B can in the physical entity identical with Node B or in the independent physical entity be separated.Can such as in order to IP version conversion or insert MGW B as media plane fire compartment wall and it can transmit media when not having code conversion.Node B instruction MGW B reserves resource towards the destination node of IP address ip A transmission media and reserves resource (step 3) for another destination node.MGW B confirms reserving and indicating it to be assigned with IP address ip B (step 4) to the second destination node of resource.According to SDP program, Node B is middle this network address IPB of insertion of SDP " c line " (owing to being ready to set up calling via its related media gateway MGW B or connect), but transmission (namely not changing) is regarded as the SDP attribute (step 5) in the unknown of Node B place pellucidly.Subsequent node MSCC has the interface with media gateway MGW C.When receiving the message sent by intermediate node B, especially, MSC C determines that content, the i.e. IPB of " c line " are not equal to the content of the verification msg in SDP attribute, i.e. IPA.Therefore, can find that the media gateway identity MGWIDA received should be used for MGW selects.On the contrary, MSC C recognizes optimization MGW and selects not applicable, removes SDP attribute from the message received.In addition, MSC C selects media gateway MGW C, and this selection can such as be determined relative to the MGW on the optimization position of the down hop of MSC C routing call.MSC C indicates MGW C reserve resource towards the destination node of IP address ip B transmission media and reserve resource for another destination node, and MGW C confirms reserving and indicating it to be assigned with IP address ip C (step 6 and 7) to the second destination node of resource.Then, its network address to its related media gateway MGW C is inserted in SDP " c line ", i.e. IPC, and passes on this SIP or SIP-I message (step 8) generated.This message can also comprise SDP attribute " mgwid " as previously mentioned.

Therefore, according to the operation of Fig. 7, MSC A be configured to transmitter side perform in the method for Fig. 2 and 3 any one, Node B is configured to not perform any one in method as herein described, and MSC C be configured to receiver side place perform Figure 4 and 5 method in any one and perform at transmitter side place in the method for Fig. 2 and 3 any one.

Fig. 8 illustrates the signaling diagram selected according to the delay media gateway of exemplary embodiment of the present invention.

According to Fig. 8, the first equipment MSC-A judges application delay MGW option program and does not select or preliminary election MGW in this stage.MSC A will not select or preliminary election media gateway to follow-up Node B instruct MS C A.This is by sending SIP (SIPINVITE) request of inviting realize to subsequent node, such as MSC B.SIP (SIP INVITE) request of inviting comprises the SDP of encapsulation, and the SDP of this encapsulation comprises " the c line " with non-assigned ip address (0.0.0.0).MSC A can also judge recommend media gateway and use new SDP attribute " mgwid " to indicate the identity of recommended MGWB.According to the present embodiment, the value of this SDP attribute comprises the non-assigned ip address identical with in " c line ", comprises unique identification MGWID B (step 1) of MGW B in addition.Receive from MSC A SIP invite (SIP INVITE) message time, MSC B by the IP address in SDP " mgwid " attribute compared with the IP address in corresponding SDP " c line ".Because two IP addresses are equal, so MGW identity MGWIDB in SDP " mgwid " attribute is used for the selection of media gateway by MSC B.It determines that it has towards the control interface of MGW B and judges reserving in this MGW place request resource.MSC B indicates MGW B to be that two interconnection destination nodes reserve resource.MGW B confirms reserving and indicating it to be assigned with IP address ip B1 and IPB2 (step 2) to destination node of resource.According to Fig. 8, network address IPB1 is for continuing the session setup process in step 3 and 4.In steps of 5, MGW B is configured to use network address IPC to send media by MSC B.It should be noted can by other signaling such as ISUP (ISDN User Part) signaling or replace step 3 to 5 towards the signaling of mobile terminal.

In step 6, Node B generates SIP or SIP-I message, is SIP 183 conversation procedure in this case, and sends it to MSC A.As non-limiting example, the message of such transmission comprises SDP data division, this SDP data division comprise describe by MGW B according to SDP " c line " (" c=") of the network address IPB2 of normal SIP/SDP regular allocation and describe preliminary election or the SDP attribute (a=mgwid) of interpolation network address IPB2 recommending MGW identity MGWIDB and correspond to preliminary election or recommendation media gateway as verification msg.According to the present embodiment, the value of this new SDP attribute " mgwid " comprises the IP address ip B2 identical with in " c line ", comprises the unique identification MGWIDB of media gateway B in addition.When receiving this message, especially, based on " c line " content, i.e. IPB2, MSC A determines that content, the i.e. IPB2 of " c line " equal the content of the verification msg in SDP attribute, i.e. IPB2.Therefore, the media gateway identity MGWIDB received is used for MGW to select.It determines that it has towards the control interface of MGW B and judges reserving in this media gateway place request resource.Its instruction MGW B reserves resource (step 7) towards the destination node of IP address ip B2 transmission media.MGW B determines that IP address ip B2 is the IP address of oneself and is configured to by certain inner shortcut this destination node to be connected with destination node reserved in step 2, thus saves outside transmission resource and internal processing resource.

Therefore, according to the operation of Fig. 8, MSC A and MSC B is configured to perform any one in the method for Fig. 2 and 3 and any one in the method for receiver side place execution Figure 4 and 5 at transmitter side place.

Fig. 9 illustrates the signaling diagram selected according to the delay media gateway with intermediate node of exemplary embodiment of the present invention.Suppose that intermediate node B does not support that the MGW based on SIP or SIP-I had according to the MGW identity of SDP coding selects.

The step 1 of Fig. 9 is equivalent to the step of Fig. 8.Then, such as SBC or SIP-ALG do not support optimization MGW to select and certain Node-B receiver SIP of relevant " mgwid " attribute invites (SIP INVITE) message and ignores " mgwid " attribute.It inserts the media gateway MGW B of oneself, and this media gateway MGW B can in the physical entity identical with Node B or in the independent physical entity be separated.Can such as in order to IP version conversion or insert MGW B as media plane fire compartment wall and it can transmit media when not having code conversion.Node B instruction MGW B is that two destination nodes reserve resource, and MGW B confirms reserving and indicating it to be assigned with IP address ip B1 and IPB2 (step 2) to this destination node of resource.In step 3, SIP invites (SIP INVITE) transfer of messages to another network equipment MSC C by Node B.SIP invites (SIP INVITE) to comprise the SDP " c line " with IP address ip B1.Because it does not understand SDP " mgwid " attribute, so Node B passes on its attribute when not modifying.Receive SIP invite (SIP INVITE) message time, MSC C by the IP address in SDP " mgwid " attribute compared with the IP address in corresponding SDP " c line ".Because two IP addresses are unequal, so the MGWID B in SDP " mgwid " attribute does not select for (in advance) of media gateway by MSC C.On the contrary, it selects media gateway MGW C.Described (in advance) selects the media gateway can such as determined on the optimization position of the down hop of the calling will set up relative to MSC C route.MSC C indicates MGW C reserve resource towards the destination node of IP address ip B1 transmission media and reserve resource (step 4) for another destination node, and MGW C confirms reserving and indicating it to be assigned with IP address ip C1 and IPC2 (step 5) to destination node of resource.In step 6 is to 8, MSC C can pass on comprise the SDP " c line " with IP address ip C1 SIP invite (SIP INVITE) message, MSC C can receive sip response message, such as " 183 conversation procedure message ", it comprises the SDP response of the IP address ip D had in " c line ", and MGW C is configured to send media towards IPD by MSC C.It should be noted can by other signaling such as ISUP (ISDN User Part) signaling or replace step 6 to 8 towards the signaling of mobile terminal.

In step 9, MSC C passes on the sip response message received in step 7.Sip response message comprises the SDP of encapsulation, and the SDP of this encapsulation comprises instruction by " the c line " of MGW C according to the IP address ip C2 of normal SIP/SDP regular allocation.MSC C also uses new SDP attribute " mgwid " to indicate the identity of MGW C.According to the present embodiment, the value of this SDP attribute comprises the IP address ip C2 identical with in " c line " as verification msg, comprises the unique identification MGWID C of media gateway MGW C in addition.In step 10, MGW B is configured to send media towards IPC2 by Node B, and in a step 11, Node B passes on sip response message towards MSC A.Sip response message comprises the SDP c line with IP address ip B2.Because it does not understand SDP " mgwid " attribute, so Node B passes on its attribute when not modifying.When receiving sip response, MSC A by the IP address in SDP " mgwid " attribute compared with the IP address in corresponding SDP c line.Because two IP addresses are unequal, so the MGWID C in SDP " mgwid " attribute is not used for the selection of media gateway by MSC A.On the contrary, it selects MGW A.This selection can such as be determined relative to MSC A from the MGW the optimization position of the previous dive of its receipt of call.MSC A indicates MGW A to reserve resource (step 12) towards the destination node of IP address ip B2 transmission media.

Therefore, according to the operation of Fig. 9, MSC A be configured to receiver side place perform Figure 4 and 5 method in any one and perform at transmitter side place in the method for Fig. 2 and 3 any one, Node B is not configured to perform any one in method as herein described, and MSC C is configured to perform any one in the method for Fig. 2 and 3 and any one in the method for receiver side place execution Figure 4 and 5 at transmitter side place.

Although " SIP invites (SIP INVITE) " and " SIP 183 conversation procedure " have been used as above wherein can the non-limiting example of message of related transmitting information, it should be noted the message that additionally or alternatively can use any kind.Such as, " SDP provides " or " SDP response " message of any kind can be applied.

Although up to the present main reference method, program and functional description embodiments of the invention, corresponding embodiment of the present invention also contains each equipment, network node, comprise its both software and hardware.

The equipment described in Figure 10 below and 11 may be implemented as the part of self-contained unit or device, the network equipment, node etc.Two shown equipment can also such as by operationally with or do not form public system with intermediate node or device coupled.Any one in illustrational square frame represents some function and can realize in hardware or in software or in a joint manner in any imaginabale mode.That is, when use hereinafter term " for ... device " time, intention contain any physics realization that can realize this type of function.These can be such as the processor, data processing unit, data generator etc. of any kind.In the sense that, term " for ... device " intention have with term " be configured to ... device " there is identical meaning and scope, wherein, device can be the physics realization of any kind.

In Figure 10 below and 11, the arrow between independent square frame represents the direction of the operability coupling between it and the data flow in these couplings, and the name of italics represents the data of transmission in some coupling.

Figure 10 illustrates the schematic block diagram of the equipment according to exemplary embodiment of the present invention.Illustrational like this equipment be configured to mode alone or in combination perform in the method for Fig. 2 and 3 any one.That is, Figure 10 also comprises two level of detail (describe with dotted line according to of Fig. 2, and describe with solid line according to of Fig. 3), must be regarded as two different embodiments of the present invention.

According to Figure 10, comprise for supplying by the device 1010 of the identity of the media gateway of preliminary election and the device 1020 for the authorization information that is provided for described preliminary election media gateway identity according to the equipment of the present embodiment, wherein, described authorization information be configured to check described in whether network entity identity is applicable to second network equipment place in advance network entity select.By the storage arrangement 1030 of the correlated results of medium gateway (in advance) option program for both devices 1010 and 1020 are submitted necessary information.That is, when (in advance) have selected media gateway, other data such as its identity and the such as network address are stored in storage arrangement 1030 for using in the future.Storage arrangement 1030 is operationally coupled with both devices 1010 and 1020 and can is permanent and provisional any kind.

According to the feeding mechanism 1010 of the present embodiment by for preferably encoding so that the device transmitted 1011 is formed to preliminary election MGW identity in some parameter in SDP attribute.

Generator 1020 according to the present embodiment is made up of the device 1021 for adding the network address of the IP address of such as preliminary election media gateway to the transformation parameter through encoding like this of such as SDP attribute.

The device 1040 (such as transmitter) for preliminary election media gateway identity and verification msg being sent to another equipment in Session initiation Protocol (SIP or SIP-I) message is also comprised according to the equipment of the present embodiment.

According to an aspect of the present invention, the described equipment network address also comprised for the IP address by such as preliminary election media gateway is defined as connection data, device 1050 preferably as SDP " c line ".If like this, then dispensing device 1040 is also configured to send this connection data in Session initiation Protocol (SIP or SIP-I) message.

Figure 11 illustrates the schematic block diagram of the equipment according to exemplary embodiment of the present invention.Illustrational like this equipment be configured to mode alone or in combination perform in the method for Figure 4 and 5 any one.That is, Figure 11 also comprises two level of detail (describe with dotted line according to of Fig. 4, and describe with solid line according to of Fig. 5), must be regarded as two different embodiments of the present invention.

According to Figure 11, comprise the device 1110 of the identity for obtaining preliminary election media gateway and the authorization information for described preliminary election media gateway identity according to the equipment of the present embodiment, and whether the preselected network entity identities obtained for coming inspection institute based on this authorization information is applicable to the device 1130 of the network entity selection at this equipment place.

According to an aspect of the present embodiment, described equipment also comprises the device (such as receiver) 1140 for receiving preliminary election media gateway identity and verification msg in Session initiation Protocol (SIP or SIP-I) message from another equipment.This type of message can such as comprise the IP address of preliminary election media gateway identity in SDP attribute and such as preliminary election media gateway the network address and as SDP connection data, the network address preferably as the IP address of the such as preliminary election media gateway of SDP " c line ".

According to Figure 11, obtaining means 1110 comprises the device 1111 of the network address for obtaining preliminary election media gateway from SDP attribute, and namely device 1111 obtains IP address as verification msg from SDP attribute.In addition, according to the verifying attachment 1130 of an embodiment by for the network address in the SDP obtained by device 1110 attribute is formed with the device 1131 mutually compared from the network address the SDP connection data (such as c line) that SDP " c line " retrieves by the indexing unit 1120 being used for retrieving this information.In addition, described equipment can comprise for show at comparison means 1131 network address equal (or, in other words, verifying attachment 1130 shows preselected network entity identities and is applicable to network entity and selects) when preliminary election media gateway identity is used for the device 1150 that media gateway selects, with for show at comparison means 1131 network address be unequal (or, in other words, verifying attachment 1130 shows preselected network entity identities and is not practicable for network entity and selects) when abandon the device 1160 of preliminary election media gateway identity.

As replacement, equipment also comprises how the result produced by comparison means 1170 all removes SDP attribute device 1170 from SIP/SIP-I message according to an embodiment of the invention.

Figure 12 illustrates schematically showing according to the data structure of exemplary embodiment of the present invention.

As Figure 12 exemplarily describes, specific data structure can be represented by SDP attribute or expansion according to an embodiment of the invention, it comprises the data representation of identity (MGW ID) of media gateway and the expression of the network address (ADDR) of media gateway, such as, for the IP address of the user-plane traffic by media gateway.Note that the equivalent terms for " network address " can be " link address ".

Therefore, according to embodiments of the invention, can with following grammer (ABNF definition in) by media webmaster identity MGW ID (namely, MGW identifier) be exemplarily encoded to following " session level " or " media-level " SDP attribute (such as, being called " mgwid "): MGW_Identifier=" a=MGW_Identifier:<connection-addressGreatT. GreaT.GT<MGW_Id> "

Son field <connection-address>, the i.e. network address can have the identical coding defined with the <connection-address> son field for the SDP c line in the 5.7th section of RFC 4566.The identity of son field <MGW_Id>, i.e. media gateway can be the eight-bit group string of any eight-bit group (octet) value comprised except 0x00 (Nu1), 0x0A (LF) and 0x0D (CR).Value as described in explaining as concentrated at standard character.It should be noted, can such as encode to son field <MGW_Id> in the mode identical with the BCU-ID in BICC, namely for representing 4 eight-bit group of network ID field and local BCU-ID field.Son field <MGWId> should comprise the unique identifier that the operator for media gateway defines.The property value of SDPMGW_Identifier attribute should not obey SDP " charset " attribute.

As mentioned above, if the <connection-address> son field of the <connection-address> son field in MGW_Identifier attribute and corresponding SDP c line is not mated, then do not support that the intermediate node of this attribute inserts something in user plane, but transmit this attribute pellucidly.

Figure 13 illustrates schematically showing according to the data structure of exemplary embodiment of the present invention.

As Figure 13 exemplarily describes, specific data structure can be represented by SIP or SIP-I message format according to an embodiment of the invention, this SIP or SIP-I message format comprises the identity (MGW ID) of the media gateway in SDP attribute section and the network address (ADDR) of media gateway, such as the IP address of the user-plane traffic by media gateway, and the network address (ADDR) of the media gateway as SDP connection data in such as SDP " c line ", such as, for the IP address of the user-plane traffic by media gateway.It should be noted that the network address in SDP attribute and SDP connection data can be equal or different, and can be inserted by different entities, as seen above by Fig. 6 to 9.

It should be noted that the data representation of Figure 12 and 13 is only illustrative, and also can be illustrated along horizontal alignment or with other order any.Further, SDP attribute/expansion and SIP/SIP-I message can before those described elements, comprise other element in-between and/or after which.

Certainly above-mentioned any function, method and operation can be realized by software and/or hardware.

Usually, it should be noted iff being suitable for performing the described function of each several part, then can be realized according to each function element in above-mentioned by any any means known in hardware and/or software respectively.Can realize described method step in independent functional block or by isolated system, or it is one or more or to come in implementation method step by single assembly in individual feature block.

In addition, may software code partition be implemented as and method step purpose processor being run at one of entity place and function are software codes has nothing to do, and the programming language of any known of such as such as Java, C++, C and assembler or following exploitation can be used to specify.May be implemented as the method step of nextport hardware component NextPort and/or equipment or device at one of entity place be hardware independent, and such as, the hardware technology of any known or following exploitation or their any mixing can be used to realize, such as MOS, CMOS, BiCMOS, ECL, TTL etc., it uses such as ASIC assembly or DSP assembly.Usually, when not changing design of the present invention, any method step is suitable for being implemented as software or being realized by hardware.Equipment and device may be implemented as independent equipment, but this does not get rid of and realizes them in a distributed way throughout whole system, as long as the function of retaining device.Should think that this type of and similar principles are known to those skilled in the art.

Software in the meaning of this explanation comprises software code, this software code similarly comprises the code device for performing each function, and the software (or computer program or computer program) embodying on the tangible medium of computer-readable recording medium such as with each data structure or the code section stored in the above or may embody in the signal or in the chips during its process.

Generally speaking, for object of the present invention mentioned above, it should be noted

Any technology of-access technology can be subscriber equipment by it can an access access network (such as via base station or be generally access node).Any current or following technology can be used, such as WLAN (wireless local access network), WiMAX (micro-wave access global inter communication), bluetooth, infrared etc.; Although above technology major part is wireless access technology, such as in different radio spectrums, access technology in the sense of the present invention can also mean wired (wirebound) technology, such as be similar to the IP-based access technology of cable system or fixed line, and circuit switching access technology; Access technology can be distinguished in such as packet switching and Circuit-switched at least two classifications or input field, but does not hinder more than the existence of the input field of two the present invention applied it,

-access network can be can be connected to and/or utilize any device of the service provided by access network, equipment, unit or means by its station, entity or other subscriber equipment; This type of service comprises data and/or (listening) visual communication, data download etc. especially;

-subscriber equipment can be can experience any device of the service from access network, equipment, unit or means, such as mobile phone, personal digital assistant PDA or computer by its system user;

-be probably implemented as software code partition and use the processor of network element or end (as the example of its device, equipment and/or module, or the example as comprising for its equipment and/or the entity of module) method step that runs is that software code has nothing to do, and any programming language that is known or following exploitation can be used to specify, as long as the function that reservation the method step defines;

-usually, when not changing the thought of the present invention of realized function aspects, any method step is suitable for being implemented as software or being realized by hardware;

-method step and/or the device of nextport hardware component NextPort may be implemented as in terminal or network element place, equipment, unit or means, or its any module is hardware independent, and the hardware technology of any known or following exploitation or its any mixing can be used to realize, such as MOS (metal-oxide semiconductor (MOS)), CMOS (complementary MOS), BiMOS (bipolar MOS), BiCMOS (bipolar CMOS), ECL (emitter coupled logic), TTL (transistor-transistor logic) etc., it uses such as ASIC (application-specific integrated circuit (integrated circuit)) assembly, FPGA (field programmable gate array) assembly, CPLD (CPLD) assembly or DSP (digital signal processor) assembly, in addition, may be implemented as any method step of component software and/or device, unit or means can such as based on any security architecture can carrying out certification, mandate, encryption (keying) and/or service protection,

-device, equipment, unit or means may be implemented as independent device, equipment, unit or means, but this distributed way not getting rid of the system that is dispersed throughout is to realize them, as long as the function of retaining device, equipment, unit or means;

-equipment can be represented by semiconductor chip, chipset or (hardware) module comprising this type of chip or chipset; But, this does not get rid of the functional realiey of equipment or module is the software in (software) module of such as computer program or computer program instead of the possibility as the hardware realized, and described computer program or computer program comprise the executable software code part for performing on a processor/running;

-such as, device can be considered as the assembly of equipment or more than one equipment, no matter it functionally cooperatively interacts or functionally separate but be in same crust of the device.

Said method step is also contained in the present invention and any of operation imagines that combination and any of above-mentioned node, equipment, module or element imagine combination, as long as applicable method and the above-mentioned of structural configuration are conceived.

Even if describe the present invention with reference to example with reference to the accompanying drawings above, but be understood that and the present invention is not limited thereto.On the contrary, it will be evident to one skilled in the art that when not departing from the scope of inventive concept disclosed herein, the present invention can be revised in many ways.

Claims

1. a network equipment system of selection, comprising:

Supply by the identity of the 3rd network equipment of first network equipment preliminary election, and

Be provided for the authorization information of described preliminary election the 3rd network equipment identity, the network equipment making it possible to check described preliminary election the 3rd network equipment identity whether to be applicable to second network equipment place is selected,

Wherein said authorization information comprises the network address of described preliminary election the 3rd network equipment.

2. the method for claim 1, also comprises:

In conversation launch protocol message, preliminary election the 3rd network equipment identity and verification msg are sent to second network equipment.

3. the method for claim 1, wherein the supply of described identity comprises:

In Session Description Protocol attribute, preliminary election the 3rd network equipment identity is encoded, and

Wherein, providing of authorization information comprises:

Add the network address of preliminary election the 3rd network equipment to described Session Description Protocol attribute.

4. method as claimed in claim 3, also comprises:

The network address of preliminary election the 3rd network equipment is defined as Session Description Protocol connection data, and

In conversation launch protocol message, the network address defined like this is sent as Session Description Protocol connection data.

5. method as claimed in claim 3, wherein, the network address of described preliminary election the 3rd network equipment comprises the Internet Protocol address for the communication via the described network equipment.

6. the method as described in any one in claim 1 to 5, wherein, performs described method by Information Mobile Service switching center equipment.

7. the method as described in any one in claim 1 to 5, wherein, performs described method in the circuit switched core network of communication system.

8. the method as described in any one in claim 1 to 5, wherein, the described network equipment is media gateway.

9. a network equipment system of selection, comprising:

Obtain by the identity of the second network equipment of the first equipment preliminary election and the authorization information for described preliminary election second network equipment identities, and

Whether the second network equipment identities carrying out inspection institute's acquisition based on described authorization information is applicable to network equipment selection,

Wherein said authorization information comprises the network address of described preliminary election second network equipment.

10. method as claimed in claim 9, also comprises:

Preliminary election second network equipment identities and verification msg is received in conversation launch protocol message.

11. methods as claimed in claim 10, wherein, described conversation launch protocol message comprises the preliminary election second network equipment identities of the preliminary election second network equipment in Session Description Protocol attribute and the network address of the network address and the preliminary election second network equipment as Session Description Protocol connection data.

12. methods as claimed in claim 11, also comprise:

From the network address of Session Description Protocol connection data retrieval preliminary election second network equipment, and

Wherein, the acquisition of described authorization information comprises:

The network address of described preliminary election second network equipment is obtained from described Session Description Protocol attribute.

13. methods as claimed in claim 12, wherein, described inspection comprises compares with the network address retrieved of Session Description Protocol connection data mutually by the network address obtained in conversation description protocol attribute.

14. methods as claimed in claim 13, also comprise:

If comparing the network address that display compares described is equal, then obtained second network equipment identities is used for the network equipment and selects, and

If this compares display, the network address is unequal, then abandon obtained second network equipment identities.

15. methods as claimed in claim 13, also comprise:

Described Session Description Protocol attribute is removed from described conversation launch protocol message.

16. methods as claimed in claim 11, wherein, the network address of described preliminary election second network equipment comprises the Internet Protocol address for the communication via the described network equipment.

17. methods as described in any one in claim 9 to 16, wherein, perform described method by Information Mobile Service switching center equipment.

18. methods as described in any one in claim 9 to 16, wherein, perform described method in the circuit switched core network of communication system.

19. methods as described in any one in claim 9 to 16, wherein, the described network equipment is media gateway.

20. 1 kinds of network equipments select equipment, comprising:

For supplying by the device of the identity of the 3rd network equipment of first network equipment preliminary election;

For the device that the authorization information being provided for described preliminary election the 3rd network equipment identity, the network equipment that makes it possible to check described preliminary election the 3rd network equipment identity whether to be applicable to second network equipment place are selected,

21. equipment as claimed in claim 20, also comprise:

For preliminary election the 3rd network equipment identity and verification msg being sent to the device of described second network equipment in conversation launch protocol message.

22. equipment as claimed in claim 20, wherein, describedly to be comprised by the device of the identity of the 3rd network equipment of first network equipment preliminary election for supplying:

For in Session Description Protocol attribute to the device that preliminary election the 3rd network equipment identity is encoded, and

Wherein, the device of the described authorization information for being provided for described preliminary election the 3rd network equipment identity comprises:

For the network address of preliminary election the 3rd network equipment being added to the device of described Session Description Protocol attribute.

23. equipment as claimed in claim 22, also comprise:

For the network address of described preliminary election the 3rd network equipment being defined as the device of Session Description Protocol connection data, wherein

The described device for preliminary election the 3rd network equipment identity and verification msg being sent to described second network equipment in conversation launch protocol message is also configured to be sent as Session Description Protocol connection data the network address defined like this in conversation launch protocol message.

24. equipment as claimed in claim 22, wherein, the network address of described preliminary election the 3rd network equipment comprises the Internet Protocol address for the communication via the described network equipment.

25. equipment as described in any one in claim 20 to 24, wherein, described equipment comprises Information Mobile Service switching center equipment.

26. equipment as described in any one in claim 20 to 24, wherein, described equipment is arranged in the circuit switched core network of communication system.

27. equipment as described in any one in claim 20 to 24, wherein, the described network equipment is media gateway.

28. 1 kinds of network equipments select equipment, comprising:

For obtaining the device by the identity of the second network equipment of the first equipment preliminary election and the authorization information for described preliminary election second network equipment identities, and

Whether the second network equipment identities obtained for coming inspection institute based on described authorization information is applicable to the device that the network equipment is selected,

29. equipment as claimed in claim 28, also comprise:

For receiving the device of preliminary election second network equipment identities and verification msg in conversation launch protocol message.

30. equipment as claimed in claim 29, wherein, the described device for receiving preliminary election second network equipment identities and verification msg in conversation launch protocol message is configured to receive conversation launch protocol message, and this conversation launch protocol message comprises the preliminary election second network equipment identities of the preliminary election second network equipment in Session Description Protocol attribute and the network address of the network address and the described preliminary election second network equipment as Session Description Protocol connection data.

31. equipment as claimed in claim 30, also comprise:

For the device of the network address from Session Description Protocol connection data retrieval preliminary election second network equipment, and

Wherein, describedly to comprise by the identity of the second network equipment of the first equipment preliminary election with for the device of the authorization information of described preliminary election second network equipment identities for obtaining:

For obtaining the device of the network address of described preliminary election second network equipment from Session Description Protocol attribute.

32. equipment as claimed in claim 31, wherein, the device whether described second network equipment identities obtained for coming inspection institute based on described authorization information is applicable to network equipment selection comprises:

For the device that the network address obtained in conversation description protocol attribute is compared mutually with the network address retrieved of Session Description Protocol connection data.

33. equipment as claimed in claim 32, also comprise:

For show at described comparison means the network address of comparing equal obtained second network equipment identities is used for the device that the network equipment selects, and

For abandoning the device of obtained second network equipment identities under show the unequal situation in the network address that compares at described comparison means.

34. equipment as claimed in claim 32, also comprise:

For removing the device of Session Description Protocol attribute from described conversation launch protocol message.

35. equipment as claimed in claim 30, wherein, the network address of described preliminary election second network equipment comprises the Internet Protocol address for the communication via the described network equipment.

36. equipment as described in any one in claim 28 to 35, wherein, described equipment comprises Information Mobile Service switching center equipment.

37. equipment as described in any one in claim 28 to 35, wherein, described equipment is arranged in the circuit switched core network of communication system.

38. equipment as described in any one in claim 28 to 35, wherein, the described network equipment is media gateway.